Thanks Tennexplorer

I had the opportunity to sit down with a disassembled 16-4 and a 19-4 this afternoon, and saw the difference in the little bump.

From what I've learned, it's possible to knock that part out of the frame and replace it with the corresponding part from a 16-4.

This afternoon i took possesion of a complete, unfired 16-4 with a broken frame. I also bought, but havent received yet, a LNIB 19-4 that has had a totalt of 50 rounds through it.

I realise that the cylinder crane is slighrly different, but that is fixable.
The "bump" I believe I can get fixed either by replacing it with the corresponding part from the 16-4 or have a replacement manufactured in a pinch.

Things are lookin up I'll post somr pictures once I get all the parts in house.